Nonmarring hammer



Sept. '10, 1 929.- J. w. WERRA NONMARRING HAMMER Filed May 14, 1927 TTQRNEYS.

Patented Sept. 10, 1929.

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JULIUS W. WERRA, OF WAUKESHA, WISCONSIN, ASSIGNOR TO WERRA ALUMINUM FOUNDRY COMPANY, OF WAUKESHA, WISCONSIN, A CORPORATION OF WISCONSIN.

NONMARRING HAMIME R.

Application filed May 14.,

This invention relates to improvements in uon-marring hammers as a new article of manufacture.

Non-marring hammers as now used are formed of copper or lead and are objectionable in many respects. Hammers formed of copper or lead are of comparatively small size for their weight, with the result that the force of the blow is applied to a small surface of the material worked on and the surface is marred, fractured, or otherwise injure'd.

It is one of the objects of this invention to provide a non-marring hammer formed of an aluminum alloy.

In forming the hammer of aluminum, it is necessary to provide for strength, ductility, uniformity, and fineness of grain, structure and toughness, and it has been found that alu1ninum and 5 to 15 per cent silicon will produce the desired result and form a metal which is relatively soft, and will deform without fracture and has high ductility, fineness of grain and high strength. The ordinary aluminum alloys, such as #12 alloy (8% copper, 92 aluminum) universally used for the general run of castings, such as automotive crank cases, gear cases, etc, have a tensile strength of around 18.000 lbs. per square inch, with 1 5% elongation, and Brinell hardness 68 to 72. These castings are comparatively weak, hard and brittle and would fracture after a comparatively few blows. The advantage of an aluminum alloy hammer over a copper hammer is apparent when it is considered that in their comparative specific gravities of 2.56 for aluminum and 8.89 for copper, the aluminum hammer would have 3% times the surface area, and the advantage over a lead hammer are still more apparent as the specific gravity of 11.37 for lead gives a comparative surface area of 4 to 1 for the aluminum hammer. Furthermore, as theelasticity of lead is practically nil, greater percentage of a driving blow is therefore effective in working the lead rather than in moving the object driven by the hammer.

It is one of the objects of the present invention to overcome the above mentioned 1927. Serial No. 181,424.

objectionable features and provide as a new article of manufacture a non-marring hammer formed of an aluminum alloy in which, for a given weight, the striking area of the hammer face is of several times the area of the ordinary hammer.

A further object of the invention is to provide as a new article ofmanufactur'e, a I

Imarring hammer as a new article ofmanufacture, and its parts and combinations as set forth in the claims, and all equivalents thereof.

In the accompanying drawing in which the same reference characters indicate the same parts in all of the views:

Fig. 1 is a side view of the improved nonmar-ring hammer;

Fig. 2 is a top view thereof;

Fig. 3 is a rear View of the upper portion thereof; and v Fig. 4 is a front View of the part shown in Fig. 3. p

In the drawing, the numeral 5 indicates the handle, which may be formed of wood or any other material desired, and 6 the head which is formed of the improved aluminum alloy. The head is shaped to provide a front flat working portion 7 of rectangular shape, and a rear flat working portion 8 of elongated form. The working faces of the head are more than three times the surface area of non-marring hammers of same weight used in standard practice, so that with a hammer of a given weight, a working surface of more than three times the area of the working surface of a hammer of standard practice is provided, thus distributing the force of the blow on a surface over a greater area.

This hammer is not a sledge hammer, but is in the hand hammer class, in which the mechanic relies rather upon his own muscular effort for the force of the blow and upon the surface area to distribute the force and prevent damage to the object worked, than he;

does upon the weight of the hammer, thus permitting the mechanic to better judge the force to be applied and to be more able to direct it.

A hammer head formed of the ordinary aluminum alloy, (8% copper and 92% aluminum), which is universally used in making castings, and which would have a tensile strength of about.l8,000 lbs. per square inch, with 1 elongation, Brinell hardness 68 to 72, would be comparatively weak, hard and brittle, and would-fracture after a comparatively few blows. Toprovide an aluminum alloy which will obtain the results desired, the aluminum is mixed with 5% to 15% silicon alloys because of their relative softness, combined with their ability to deform without fracture, their high ductility, fineness of grain and high strength. These alloys range in tensile strength from 15,000 lbs. per square inch with 12% elongation, Brinell hardness j second or 13% alloy is used for hammers used 40 for the low silicon (5%) content, to 26,500 lbs. per square inch, with 8% elongation, Brinell hardness 52, for the high silicon (13%) content. The first or 5 alloy is used for hammers for light soft work, while the for hard driving or hard material. In some cases a wider range of percentage of alloys.

used may be desirable, but in all cases the resultant hammers will have working faces of several times the area of the working faces of standard practice hammers of approximately the same weight. 1 i

As an example of the differences between the improved hammer and the hammer of standard practice, the improved hammer of one size is formed with a working face of 1%" X2" by'5 long, and weighs 1 4 lbs. A copper hammer of the same dimensions would weigh 5 4 lbs, and a lead hammer 6% lbs.

It will thus be seen that as a new article of manufacture, a non-marring hammer is provided of greater working surface and lighter in weight, and is therefore better balanced than the lead and copper hammers of standard practice, and due to the novel composition used, is still soft, strong and ductile, and is well adapted for the purpose desired.

lVhat- I claim as my invention is:

1. As a new article ofmanufacture, a nonmarring hammer formed of aluminum and two to fifteen per cent of silicon alloy to providera hammer of considerably less weight and a working face of considerably larger area than a corresponding non-marring hand hammer of standard practice, and a handle for said hammer.

2. As a new article of manufacture, a n0nmarring hammer formed of aluminum and two to fifteen per cent of silicon alloy to provide a hammer of considerably less weight and working faces at its opposite ends of considerably larger areas than a corresponding JULIUS VJ. WERRA. 

